INVESTIGATIONS ON PLASTIC RUBBER MODIFIED BITUMEN FOR PAVEMENT APPLICATIONS IN INDIA

摘要

This paper presents laboratory investigations on Plastic-Rubber Modified Bitumen (PRMB), a modified asphalt binder that was produced with waste plastics and Crumb Rubber (CR) inclusions obtained from discarded tires and additives. The final proportions of waste components and additives were reported as 90 and 10% in the total 100% blend of PRMB. A detailed laboratory study was conducted to obtain the fundamental consistency and advanced rheological characteristics of the developed PRMB and compared with Viscosity Graded (VG 30) binder, Crumb Rubber Modified Bitumen (CRMB 60), and Polymer Modified Bitumen (PMB). The softening point temperatures and viscosities at elevated temperatures of PRMB were found to be higher than VG 30 and CRMB 60. Additionally, the viscosity of PRMB at 150℃ was about 1.04 Pa.s, which was less the maximum value of 1.2 Pa.s specified for PMB 70-10 and PMB 76-10 in IS:15462-2019. Based on the results of upper Performance Grade (PG), failure temperature (PG 88-XX), and loss in the elastic recovery (＜75%) for different traffic loading conditions, it was concluded that PRMB is capable of resisting rutting and may not require any maintenance during the earlier stages of service life, i.e., immediately after opening to traffic, if appropriate quality control measures are in place. As part of future investigations, PRMB needs to be tested across a wide range of temperatures to as certain the mix performance blended with various aggregate gradations for different loading and aging conditions, while also analyzing the cost-effectiveness and environmental implications through lifecycle methods. It is envisioned that detailed studies on PRMB are necessary to classify the material and its associated mixtures as potential green / sustainable paving products/technologies.